Yarn tension regulator



April 10, 1956 N. E. KLEIN 2,741,443

YARN TENSION REGULATOR Filed Feb. 29, 1952 V 2 Sheets-Sheet 1 AIR NORMAN 6 KL E/N.

INVENTOR.

avffmukw ATTORNEYS April 10, 1956 N. E. KLEIN 2,741,443

YARN TENSION REGULATOR Filed Feb. 29, 1952 2 Sheets-Sheet 2 NORMAN E. KLEIN,

INVENTOR.

ATTORNEYS United States Patent I 2,741,443 YARN TENSION REGULATOR Norman E. Klein, Pendleton, S. C., assignor to Deering Milliken Research Corporation, Pendieton, S. C., a corporation of Delaware Application February 29, 1952, Serial No. 274,157 12 Claims. (Cl. 242-147) This invention relates to textile yarn tension devices and more especially to a method and means for regulating and maintaining uniform tension in a moving strand of yarn.

Heretofore, yarn tension devices have comprised moving mechanical parts which have resulted in slow or sluggish response in the regulation of yarn tension. Accordingly, it is an object of this invention to provide a novel yarn tension regulator of simple construction which is devoid of any mechanical moving parts other than the yarn itself and which facilitates threading of the yarn therethrough.

It is a further object of the invention to improve the yarn handling ability of a yarn tension regulator particularly in respect to the handling of yarn at a higher speed with low abrasion.

It is also an object of my invention to provide an improved yarn tension regulator which will more effectively handle yarn of low twist.

Another object of the invention is to improve the response characteristic of a yarn tension regulator so as to accomplish closer regulation of tension during rapid changes in tension.

A still further object of the invention is the provision of a method of maintaining substantially constant tension in a moving strand of yarn in which the strand whileconfined against lateral movement is resiliently urged against a plurality of spaced parallel tensioning members by means of a compressed fluid medium.

These as well as other objects and advantages will become apparent from the description of the invention which follows.

In general, the structure whereby the foregoing objects of the invention are accomplished comprises a pairof closely spaced yarn guide members having substantially fiat proximate surfaces between which a generally arcuate row of spaced yarn tensioning pins is disposed and wherein means are provided for introducing compressed air between the closely spaced yarn guide members at a point inwardly and substantially radially of the arcuately spaced pins whereby the compressed air will pass outwardly between the pins. Thus, one or more strands of yarn may be passed inwardly of the row of pins and, as the compressed air passes outwardly between the pins, it causes the yarn to run against the inner surfaces of the pins and to bulge or balloon outwardly between adjacent pins. The tension in the yarn moving in engagement with the pins is commensurate with the bulging or ballooning of the yarns between adjacent pins, caused by the force of the compressed air moving between the pins, and the collective peripheral area of the pins which is frictionally engaged by the yarn as it passes thereby.

The invention is more specifically described in connection with the accompanying drawings in which:

Figure 1 is a schematic illustration showing a typical manner in which the improved yarn tension regulator may be employed and illustrating schematically a machine with which the yarn tension regulator may be employed;

2,741,443 Patented Apr. 10, 1956 Figure 2 is an enlarged elevation of the improved yarn tension regulator looking substantially along the line 2-2 in Figure 1 but omitting the yarn therefrom for purposes of clarity;

Figure 3 is an enlarged elevation with parts in section looking along the line 3-3 in Figure 2;

Figure 4 is an elevation of the upper right-hand portion of Figure 2 but showing the yarn tension pins withdrawn from between the yarn guide members;

Figure 5 is an enlarged fragmentary elevation of the upper left-hand portion of Figure 1 and also looking at the right-hand side of Figure 2;

Figure 6 is an enlarged vertical sectional view, with parts broken away, taken substantially along the line 66 in Figure 5; and

Figure 7 is an enlarged vertical sectional view taken substantially along the line 77 in Figure 2 and showing the yarn passing through the yarn tension regulator.

Referring more specifically to the drawings, there is shown in Figure 1 a typical yarn take-up machine 10 with which the improved yarn tension regulator may be employed. In this instance, the machine 10 is shown as a quill or bobbin winding machine having a housing 11 with suitable gearing therein, not shown, for imparting rotation to the bobbin or quill 12 as one or more strands I of yarn Y are directed thereto from a bobbin, pin or spool 13. The bobbin or quill 12 exemplifies any suitable means for taking up the yarn Y under tension and the spool 13 exemplifies any suitable yarn let-oft means.

ably secured to a base member 15. The base member 15 I has a standard 16 fixed thereon, to the upper end of which a yarn guide or yarn tension regulator support 17 is suitably secured. The yarn guide or regulator support 17 has a suitable yarn guide or eye 20 therein through which the yarn Y passes in its travel from the bobbin or spool 13 to a conventional fixed pre-tension device, generally designated at 21. The yarn then passes through the yarn tension regulator broadly designated at 22. The tension device 21 may be of the usual spring pressed friction disc type or of any desired structure, being suitably supported on a bracket 23 which extends downwardly and is suitably secured to the upper surface of the tension regulator support 17.

Although it is preferable that a tension device, such as the device 21, be employed in association with the yarn tension regulator, it is evident that the yarn Y may pass directly from the yarn guide 20 to the yarn tension regulator 22. The yarn then passes through the yarn tension regulator 22 and to the rotating bobbin or quill 12.

The yarn tension regulator shown in Figures 2 to 7, inclusive, comprises a first yarn guide member or sector plate 25 and a second yarn guide member 26 disposed in closely spaced relation to each other to form a yarn receiving groove or slot therebetween. These yarn guide members 25 and 26 have fiat proximate surfaces and are shown in the form of segmental or substantially quarter-v or sector plate 25. The horizontal leg of the substantially placement of the yarn with a minimum consumption of L-shaped bracket 27 is suitably secured, as by screws 31,

to the upper surface of the horizontally disposed tension regulator support 17.

The yarn Y passes between the yarn guide members 25 and 26 and, although the yarn must be permitted to pass between the yarn guide members or sector plates 25 and 26 freely, there should be a minimum of clearance be--- tween the yarn and the yarn guide members or sector; plates 25 and 26 in order to effect a maximum radial disgran ee compressed air. The diameter of the yarn may be determined by any suitable means, such as by the use of a filometer of the photoelectric type, and a shim or spacing plate 33 (Figure 6,) of a preferable thickness of from 0.001 {00.005 inch greater than the diameter of the. yarn, is clampingly secured between the plates or yarn guide members 25 and 26 by any suitable means such as the two screws 30. The shim is so located with respect to the sector plates that it does not interfere with the passage of the yarn along its arcuate path and, in this insta nccIi S disposed adjacent the ends of the plates remote from the outer curved surfaces. Alternately, the shin} or spacing member 33 may be secured to one. or the other or both of theyarn guide members or sectorplates 25, and Z Gby means other than the screws 3 0,, ifdesired,

le se c trml f m h h m o s as na m mb 3 s a plur i y o arwa sly c d am. e sioni ie em there being five of these pins shown in the present. in-. stance and which are indicated at 34 to 38, inclusive. l i t n 3 o 38, inc us v ar c rs a n cro ssec ti n are preferably of the same diameter.

D sea d ad e t the ingress a e re openin a t Op s e en 9 th ram u de mbe s or sector plates 25 and 26 and opposite ends of the shim 33, a arn supp r r nn imi P n 1. nd. 2, esp ctively, the pins 41 and 42, as shown in Figures 3 and; 7, be n spa ed inwardly, l y of th ua P n few to; permit the yarn Y to pass therebetween, but outwardly of 33 to m ta he ram u of n a ith the him-j pposite en s o t Pi s 1 an .2 may e ecured to the sector plates or yarn guide members; 25 and 26. in any desired manner and it is preferred that one end of each of the pins 41 and 42 be secured, as by;- a pressed fit, in the second or inner sector plate 26, withthe. other. ends slidably embedded in the first sector P a e The, pins 54 to 38, inclusive, may be secured at opposite ends thereof in the sector plates or yarn guide mem-. bers 25 and 26. However, in order to facilitate threading the. yarn through the yarn tension regulator between the pins 34, to 38, inclusive, and the inner limit pins 41 and 42 it is preferred that the pins 34 to 38, inclusive, be slidably mounted in the sector plates or yarn guide members 25. and 26 so that they may readily be withdrawnfrom between thev plates 25 and 26.

To this end, in the preferred embodiment of the invention, corresponding ends of the pins 34 to 33, inclusive, are slidably embedded in the first sector plate or; yarn guide member 25 and slidably penetrate the second yarn guide member or sector plate 26. The other ends of the1 tensioning pins are suitably secured to a common header plate 44 which may be. of substantially the same configuration as. the yarn guide members 25 and 26 and is nor'ir allyv urged against the corresponding outer surface of the second yarn guide member 26 by means tov be dessr bsd- In this instance, in order to facilitate securing each of the pins 34 to 38, inclusive, to the header plate 44, each of these pins has a reduced portion 45 integral therewith which is spaced a short distance from one end thereof. The endv of each pin having the reduced section is inserted into an aperture of slightly larger diameter than that of they pin provided on the header plate 44 and the portion of the plate 44 adjacent the aperture is swaged in order to, loosely support the pin. After swaging the diameter of the aperture is less than that of the pin but greater than that of the reduced section of the pin, thus providing a loose fit between the pin and plate. The headerplate 44: is suitably secured, as by welding, to a tubular control member or header plate support 47 which has an enlarged portion 50 at the end thereof remote from the header plate 44. The tubular control member. 47 and the header plate 44 are mounted for longitudinal sliding movement on a hollow shaft 51, one end of which is suitably secured to the second yarn guide member or sector plate 26. In this instance, one end of the shaft 51 is threadably secured in the second yarn guide member or sector plate 26.

The inner face of the second yarn guide member or sector plate 26 is provided with an arcuate groove 52 therein, opposite ends of which terminate substantially short of the ingress and egress openings in the yarn tension regulator 22 and the shaft 51 is located adjacent one end of the arcuate groove 52. It will be noted that the arcuate groove 52 is relatively deep at its end adjacent the shaft 51 and tapers to zero depth at its other end. The groove 52 is spaced inwardly of the general arcuate configuration of the row of pins 34 to 38, inclusive, and a longitudinally extending passageway or bore 53 of the shaft 51 communicates with the arcuate groove 52 in the second yarn guide member or sector plate 26.

The end of the passageway 53 remote from the second yarn guide member or sector plate 26 is closed and the enlarged portion 5.0 of the tubular control member or header plate support 47 is provided with a passageway 54 which normally registers with a passageway 55 in one side of the shaft 51 to establish communication between the passageway 53 in the shaft 51 and the passageway 54 in the enlarged portion 50 of the tubular control member 47.

It will be noted in Figure 6 that the passageway 55 is in alinement with the passageway 54 when the; header plate 44 is in engagement with the outer surface of the second yarn guide member or sector plate 26. The header plate 4.4 is normally held against the outer surface of the second yarn guide memberor sector plate 26 by a compression spring 56 which surrounds the portion of the shaft 51 which projects beyond the tubular control member 47 and one end of the compression spring 56 bears against an adjustable stop. member in the form of a washer 5'7 held in the desired adjusted position by a nut 60;.

It is evident that the washer 57 may be omittedv if the diameter of the nut 60 is greater than the diameter of the spring 56. The end of the compression spring 56 remote from the washer 57 may bear directly against, the outer surface. of the enlarged portion 50. of the tubular control member 47, however, in this instance, the outer end of the enlarged portion 50 of the tubular control member 47 is provided with a circular cavity 61 in which a packing gland 62 is disposed, this packing gland 62 being held in the cavity 61 by the compression spring 56. The packing gland 62 may be of any desired material, such fifgltheif, felt and the like, and. is provided to prevent compressed air from passing outwardly between the shaft 51 and the enlarged portion 50 of the tubular control member or header plate support 47.

Secured to the enlarged portion 50 of the. tubular control member 47, and communicating with the passageway 54, is a flexible hose member 64 which may be. connected directly to a suitable source of compressed air. As shown in the drawings, however, it is preferred that a suitable air pressure indicating gauge and a pressure regulating valve be interposed in the pipe line from the source of compressed airto the hose 64. Accordingly, the hose. 64. maybe connected to a pipe T 65, to the opposite end of which, an air pressure indicating gauge seer any de; sired construction, is connected.

The branch of the pipe I has. one end of a pipe 67 connected: thereto, the oppositeend of which is connected to a manually controlled air pressure regulating valve 70 which may. also be of conventional or any other de; sired construction, The side of the air pressure rcgulat-. ing valve, 70) rem te from the pipe 67 is connected to a pipe 71 communicating with a" suitable source of compressed air asindicated by the arrow in Figure 2.

It will be, observed that the yarn passes upwardly from the pir t bs bb n F u e 1, t r h w e ram, u d 29. a d fl ro sh h m. n i n desa 1 music r ate a ma l amoun of nput o ereen i na he v -n p or. o hey n p g: e wee he yarn guide members 25 and 26. In order to thread the yarn Y between the yarn guide members or sector plates- 25 and 26, an operator may grasp theenlarged portion 50 of the tubular control member or header plate support 47 and, by causing relative movement between the header plate support 47 and the shaft 51, that is, by moving the header plate support 47 relative to the shaft 51, the passageway 54 in the enlarged portion 50 of the header plate support 47 is moved out of registration with the passageway 55 in the shaft 51.

This prevents compressed air from passing through the passageway 53 in the shaft 51 and between the yarn guide members or sector plates 25 and 26. It also moves the header plate 44 and the corresponding pins 34 to 38, inclusive, outwardly relative to the yarn guide members or sector plates 25 and 26, the header plate 44 being moved sufficiently so that the free ends of the pins 34 to 38, inclusive, do not span the space between the proximate faces of the yarn guide members or sector plates 25 and 26. The upper edges of the sector plates 25 and 26 are preferably rounded, as at 72, at least adjacent the ingress end of the yarn tension regulator, to facilitate insertion of the yarn Y between the sector plates 25 and 26.

The yarn Y is first inserted between the sector plates 25 and 26 andthen moved downwardly between the plates and into engagement with the yarn support pins 41 and 42, which causes the yarn to change direction or to be bent at an angle of substantially ninety degrees. It is evident that the yarn tension regulator may be constructed to effect a greater or lesser angle in the bend of the yarn Y as it passes therethrough, if desired.

The operator may then release the enlarged portion 50 of the tubular control member or header plate support 47 thus permitting the pins 34 to 38, inclusive, to again span the distance between the sector plates 25 and 26.

Now, assume that compressed air is permitted to pass from the pipe 71, through regulating valve 70, pipe 67, pipe T 65 and hose 64 to the passageway 54 in the enlarged portion 50 of the tubular control member or header plate support 47. If the passageway 55 registers with the passageway 54, compressed air passes through the passageways 55 and 53, successively, in the shaft 51 and is thus distributed by the groove 52 in the inner face of the yarn guide member or sector plate 26 and by the shim 33. This causes the compressed air to fan outwardly substantially radially of the common center point of the arcuate line of the row of pins 34 to 38, inclusive. The yarn Y will thus be caused to balloon outwardly between adjacent pins 34 to 38, inclusive, to thereby partially wrap around each of the pins 34 to 38, inclusive. The degree of ballooning varies with the pressure of the compressed air.

The object of this invention is not only to control the amount of tension in the yarn but to also maintain the yarn at a substantially uniform output tension although the input tension in the yarn may fluctuate. Of course, the input tension in the yarn is determined by the tension device 21, or in lieu of the tension device, by the tension in the yarn due to the friction of the adjacent convolutions of yarn wound about the bobbin 13 and the friction of the yarn passing through the yarn guide 20 (Figure 1).

There are several contributing factors which determine the output tension of the yarn; that is, the tension of the yarn as it leaves the pin 38 at the egress end of the yarn tension regulator. Among these are the distance between adjacent pins, the coefiicient of friction and the peripheral portion of each yarn tensioning pin which is engaged by the yarn as it moves in frictional engagement therewith, the latter being determined by the pressure of the compressed air passing outwardly between adjacent pins.

It is evident that the greater the number of pins employed in the yarn tension regulator, the greater will be the tension effected in the yarn Y passing through the yarn tension regulator since the tension in the yarn progressively increases as it moves from between the first pair of adjacent pins 34 and 35 to between the next adjacent pair-of pins 35 and 36 and so on through the yarn tension regulator. 1

The mathematical foundation for the present invention is the organic growth formula, as can be found on In the above formula, E is the output tension in the yarn at the egress and of the yarn tension regulator, I is the input tension at the ingress end of the yarn tension regulator, e is a constant (2.718), f is the coefiicient of friction of the particular type of yarn passed through the yarn tension regulator and a is the angle in radians according to the portion of the pins engaged by the yarn. From the above formula, it is evident that tension in the yam, as it progresses from one pin to the next, increases in accordance with the exponential function fa. The an le a is determined by such factors as input tension, spacing between the pins and the air pressure. The greater the input tension, the straighter the yarn path becomes and the less the wrap-around of the yarn relative to the pins which, in turn, lowers the tension component contributed by the pin system. A balanced control action is thereby gained such that the output tension remains substantially constant although the input tension may vary up to a value equivalent to approximately seventy-five per cent of the output tension setting. The tension level is established by providing a specific airpressure. Accordingly, the greater the air pressure, the greater the output tension of the yarn.

For example, if the coefficient of friction between the yarn and the surface of the pins is taken as .3, the total angle of wrap-around as averaging 27r radians or 360, and the input tension is assumed constant at 2 gm., the output tension is approximately 13.

The angle a employed in the above formula, it treated as the sum of the angles of wrap of the yarn on all of the pins 34 to 38, inclusive, results in a gain factor ratio between the input tension and the output tension of the yarn passing through the yarn tension regulator 22. v

When the air pressure regulator valve 70 is closed, it is evident that the yarn would then slide upon the lower limit or yarn support pins 41 and 42. Therefore, it is evident that the tension in the yarn would be slightly greater at zero air pressure than it would at a low pressure of, say, five pounds per square inch gauge pressure, since, at zero air pressure, the yarn is actually wrappedapproximately ninety degrees about the lower limit or yarn support pins 41 and 42 while, in the case of approximately five pounds per square inch gauge air pressure being emitted through the passageway 53 in the shaft 51, the yarn actually rides on the compressed air so that the tension induced in the yarn is considerably reduced.

Obviously, the configuration and size of the sector plates 25 and 26 may vary as well as the number of yarn tensioning pins, the diameter of the yarn tensioning pins and the spacing of the yarn tensioning pins. The spacing between adjacent pins may also vary progressively from one end of the pin array to the other.

Although the arcuate configuration of the row of pins 34 to 38, inclusive, is formed about a common center point, it is evident that the pins 34 to 38, inclusive, may be formed in a row defining a general curve or, if so desired, some of the pins may be arranged in a straight line. However, a uniformly curved row of pins is desirable so that in the case where the input tension is approaching the maximum and the tension added by the array is therefore desired to be at aminimum, the forces tending to pull the yarn away from the array are equal per unit length of yarn and counteract a uniform air ttfMlAdt-i r' pressure whereby the arc of travel is essentially stabilized in a position or form incurring minimum tension, i. e., yarn riding on air between pin array proper and lirnitpins. In addition, the uniformly curved row makes for ease of design andconstruction.

Where the use to which the regulatoris' put is such that the yarn to be regulated is likely to have knots therein, it is desirable to provide an arcuate groove to permit the passage of such knots through the, device, the, groove, being parallel to. the curved rowof pins 34.38 and located between these pins, and the inner limit pins 41 and 42, as shown in Figure 7' at '75. TheI size of the groove will obviously vary with the, diameter of the yarn and the type of knot normally employed in joining the free ends of a, broken, strand together. Generally, a groove having a cross-sectional; area of fourto five times the maximum diameter of the yarn is satisfactory. it may be formed in the internal face of either of the sector plates 25 and 26 alone. or partially in each and is preferably tapered outwardly adjacent the ingress end to provide a funnelor trumpet-shaped mouth, as at 76, thus facilitating the en trance; of a knot therein. The side walls of the groove at their intersection with the face of the plate should be substantially at right angles thereto inorder to prevent wedging of the knot which would occur if the groove walls were inclined.

It is thus seen that there is provided an improved yarn tension regulator for maintaining a uniform output tension in the yarn passing therethrough although the input tension may vary considerably and also for maintaining the output tension at a uniform tension proportionate to the optimum input tension of the yarn as it passes through the. yarn tension regulator. It is evident that the greater the number of tensioning pins employed, the more constant will be, the output tension in the yarn in proportion to the optimum input tension of the yarn.

In the drawings and specification, there has been set forth a preferred embodiment of the invention and although specific terms are employed, they are used in a generic and descriptive sense only, and not for purposes of; limitation, the scope of the invention being defined in thecla-ims.

Lelairn 1. Apparatus for regulating the tension in moving strands of yarn; comprising a pair of closely spaced yarn guide members between which the yarn may be moved,

a plurality of pins spanning the distance between said yarnguide members and being positioned on one side of the yarn, and, means for directing compressed air against the other side of the, yarn to cause the yarn to frictionally engage said. pins, whereby said pinsv serve to dampen the fluctuations in the tension: of; said yarn, the internal face of at; least one of said membersbeing provided with a groove for-med, substantially parallel to said plurality of pins and adjacent theside thereof engaged by the yarn, said groove having an out-wa ydly tapering mouth at its ingress end.

. 2. Apparatus for regulating the tension in a moving strand of yarn comprising regulator means having a slot therein through which the yarn may be passed, a plura'liiy' Qfi yarn tensioning pin-s positioned in said regulator means; and, spanning said slot and being disposed on one side of; said yarn, means for introducing air under-pressure into, said slot at the other side of said yarn to cause the yarn to frictionally engage said pins as it passes thereby, and said pins being movable out ofsaid slot for threadingthe yarn into said slot.

3". Apparatus for regulating tension in moving yarn comprising a pair of yarn guide members, means securing said yarn. guide members in closely spaced relation to. each. other, said guide members having a plurality of pin receiving bores therein, a header plate, a plurality of yarn tension pins secured to said header plate and being slidably' disposed in the bores in said yarn guide members ands spanning. the distance between said members, said head'ei plate being movable relative to said yarn guide Gil members to permit said pins to be removed from between said yarn guide members for threading purposes, said pins being positioned on one side of the yarn passing through said apparatus, and means for introducing air under pressure between said' yarn guide members on the other side ofsaid yarn to cause said yarn to friction-ally engage said pins and to balloon therebetween as it passes through the apparatus.

4. Apparatus for regulating tension in moving yarn comprising a pair of yarn guide members disposed in closely spaced relation to each other, a shim positioned between said yarn guide members and determining the spacing therebetween, said guide members having a plurality of pin receiving bores therein, a header plate, a plurality of yarn tension pins secured to said header plate and being slidably disposed in the bores in said yarn guide members and spanning the distance between said members, said header plate being movable relative to said yarn guide members to permit said pins to be removed from between said yarn guide members for threading purposes, said pins being; positioned on one side of the yarn passing through said apparatus, means for introducing air under pressure between said yarn guide members on the other side of said yarn to cause said yarn to fric-tionally engage said pins and to balloon there'between as it passes through the apparatus and, at least one of said yarn guide members having an air distribution groove in the inner face thereof to which the air is initially directed to distribute said air to all of said pins.

5. Apparatus for regulating tension in moving yarn comprising a pair of yarn guide members disposed in closely spaced relation to each other, a shim positioned between yarn guide members and determining the spacing therebetween, said guide members having a plurality of pin receiving bores therein, a header plate, a plurality of yarn tension pins secured to said header plate and being' sl'idably disposed in the bores in said yarn guide members and spanning the distance between said members, said header plate being movable relative to said yarn guide members to permit said pins to be removed from between said yarn guide members for threading purposes, said pins being positioned on one side of the yarn passing through said apparatus, at least one of said yarn guide members having an air distribution groove in the inner face thereof, means for directing air under pressure to the air distribution groove to, in turn, distribute said air to all of said pins and to cause said yarn to frictional'ly engage said pins and to balloon therebetween as it passes through the apparatus, and means associated with said header plate for cutting oh" the air upon said pins being removed from between the yarn guide members.

6. An improved yarn tension regulator for maintaining uniform tension in a moving strand of yarn comprising a pair of closely spaced yarn guide members having relatively flat proximate surfaces, a curved row of spaced yarn tensioning pins supported by at least one of said yarn guide members and spanning the distance between the proximate surfaces of the yarn guide members, and means for introducing compressed air between the proximate faces of the yarn guide members at a point inwardly of the curved row of spaced yarn tensioning pins whereby the yarn may be passed between the yarn guide members inwardly of the row of pins and, upon compressed air being introduced between the yarn guide members, the compressed air will pass; outwardly between adjacent pins to cause the yarn to balloon outwardly between adjacent pins to thus effect a uniform tension in the yarn as it passes through the yarn tension regulator.

7. Apparatus for maintaining uniform tension in a strand of yarn passing from a source of yarn to a take up means for the yarn comprising a pair of closely spaced plates, a plurality" of spaced pins arranged in an arcuate row between said plates, said row of spaced pins extending forwardly and downwardly relative to the direction of movement of the yarn, a spacing member disposed between said plates and having opposite ends thereof terminating closely adjacent the endmost pins in said arcuate row of pins, and means for introducing compressed air between the plates at a point between the arcuate row of pins and the spacing member whereby the yarn may pass from the source between the pins and the point from whence the compressed air is directed and then to the take-up means and the compressed air will pass outwardly between adjacent pins in said row to cause the yarn to engage said pins and to balloon outwardly between adjacent pins to efiect uniform tension in the yarn.

8. An improved yarn tension regulator for maintaining tension in a moving strand of yarn comprising a pair of closely spaced yarn guide members having relatively fiat proximate surfaces, a curved row of spaced yarn tensioning pins supported by at least one of said yarn guide members and spanning the distance between the proximate surfaces of the yarn guide members, at least one yarn support pin disposed at each end of the yarn guide members inwardly of the corresponding yarn tensioning pins and spanning the distance between and being connected to the yarn guide members, and means for introducing compressed air between the proximate faces of the yarn guide members at a point inwardly of the curved row of spaced yarn tensioning pins and directing the compressed air outwardly whereby the yarn may be passed through the yarn tension regulator between the tensioning pins and the yarn support pins and, upon compressed air being introduced between the yarn guide members, the compressed air will pass outwardly between adjacent yarn tensioning pins to cause the yarn to engage the same and to balloon outwardly therebetween to give a uniform tension to the yarn as it passes through the yarn tension regulator.

9. The device as in claim 8 wherein at least one of said guide members is provided on its proximate face with a groove substantially parallel to said curved row of pins, said groove being disposed intermediate said row and said support pins and having a funnel-shaped mouth at its ingress end.

10. In a structure according to claim 8, manually operable means for at least partially withdrawing the yarn tensioning pins from the corresponding yarn guide member axially of the yarn tensioning pins to thereby move the latter out of the space between the yarn guide members to facilitate threading the yarn between the yarn guide members.

11. In a structure according to claim 10, spring means normally urging said yarn tensioning pins into position spanning the distance between the yarn guide members to return the yarn tensioning pins to the later position upon said manually operable means being released by an operator.

12. In a yarn tension regulating device the combination of a pair of spaced support plates, between which the yarn may be moved, a plurality of yarn engaging pin members carried by one of said plates, the other of said plates having a plurality of corresponding bores to receive the unsupported ends of said pin members, means for directing a fluid against the yarn passing between said plates to cause the yarn to frictionally engage said pin members, and .a replaceable spacing shim to determine the distance between said plate members, whereby said tension regulating device can readily be employed with yarns of varying diameters by utilizing shims of different thicknesses.

References Cited in the file of this patent UNITED STATES PATENTS 1,046,822 Madden Dec. 10, 1912 1,399,521 Rodger Dec. 6, 1921 1,602,447 Olson Oct. 12, 1926 1,762,476 Houghton June 10, 1930 2,301,249 Butterworth Nov. 10, 1942 2,393,243 Franz Jan. 22, 1946 2,447,982 Koster Aug. 24, 1948 FOREIGN PATENTS 230,477 Switzerland Mar. 16, 1944 

1. APPARATUS FOR REGULATING THE TENSION IN MOVING STRANDS OF YARN COMPRISING A PAIR OF CLOSELY SPACED YARN GUIDE MEMBERS BETWEEN WHICH THE YARN MAY BE MOVED, A PLURALITY OF PINS SPANNING THE DISTANCE BETWEEN SAID YARN GUIDE MEMBERS AND BEING POSITIONED ON ONE SIDE OF THE YARN, AND MEANS FOR DIRECTING COMPRESSED AIR AGAINST THE OTHER SIDE OF THE YARN TO CAUSE THE YARN TO FRICTIONALLY ENGAGE SAID PINS, WHEREBY SAID PINS SERVE TO DAMPEN THE FLUCTUATIONS IN THE TENSION OF SAID YARN, THE INTERNAL FACE OF AT LEAST ONE OF SAID MEMBERS BEING PROVIDED WITH A GROOVE FORMED SUBSTANTIALLY PARALLEL TO SAID PLURALITY OF PINS AND ADJACENT THE SIDE THEREOF ENGAGED BY THE YARN, SAID GROOVE HAVING AN OUTWARDLY TAPERING MOUTH AT ITS INGRESS END. 